Author Topic: 750f0 - two month production? (Read 4116 times)

sixthwisconsin · « **on:** March 13, 2019, 07:03:13 AM »

I've often wondered why the 1975 cb750f was only listed as January & Febuary 1975 production. It looks like the only difference was green gauge faces and different color offerings between F0 & F1.

My bike has a manufacture date of 5/75 and an F1 frame number of 2007613 but an F0 engine number of 2507894. Don't know if this was common for the early F1 bikes or mine was swapped out at some point.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #1 on:** March 13, 2019, 11:41:32 AM »

I've seen pictures of 1975 CB750F0's dated April 75 on the VIN tag.

That chart would indicate there were 115081 75 750F engines produced. My take is it should read 2515085. Not at home near my 2 75's or my literature.

The 76 changed colors and gauge colors and was also produced in 4/75.

sixthwisconsin · « **Reply #2 on:** March 13, 2019, 04:10:44 PM »

Quote from: Jerry Rxman Griffin aka MuthaF'er on March 13, 2019, 11:41:32 AM

I've seen pictures of 1975 CB750F0's dated April 75 on the VIN tag.

That chart would indicate there were 115081 75 750F engines produced. My take is it should read 2515085. Not at home near my 2 75's or my literature.

The 76 changed colors and gauge colors and was also produced in 4/75.

The total 1975f0 production run is listed at 15,000. How does that jive with the engine # spread?? The more I look at this the less sense it makes. And did they only make orange & Blue in Jan & Feb 1975? Red & yellow in 1976?

Jerry Rxman Griffin aka MuthaF'er · « **Reply #3 on:** March 13, 2019, 05:14:03 PM »

15054 but who's counting. The engine spread is similar. My bike is 1606 and it's engine is 1954. The other is mid run around 7000 - 8000. The 75 run was blue and orange and it changed to red and yellow in mid April.

Where is your chart from? Honda chopper? I have seen inconsistencies in info before.

My Honda service manual and/or the corresponding parts book have the exact serial numbers but I am 3000 miles away……..

sixthwisconsin · « **Reply #4 on:** March 13, 2019, 05:24:50 PM »

I was looking at this:
http://www.sohc4.net/cb750f-model-guide
Still wondering if my bike was born like this or if the motor was swapped at some point. Thinking it came from Honda like this.

Don R · « **Reply #5 on:** March 13, 2019, 05:57:32 PM »

Honda built bikes however they had to. Cranking them out was job one. As parts ran out, a batch of new might come in before the last batch of old.

sixthwisconsin · « **Reply #6 on:** March 13, 2019, 06:11:55 PM »

Don,
I am thinking it was born with an F0 engine in an F1 frame. I have absolutely no confirmation of this but manufacturing being what it is, I have no reason to believe otherwise. Its titled as a 1975 but that has no bearing on this conversation.

The question is why did Honda limit F0 production to 2 months?

jlh3rd · « **Reply #7 on:** March 13, 2019, 06:18:08 PM »

I stumbled across this...

jlh3rd · « **Reply #8 on:** March 13, 2019, 06:21:06 PM »

this is from honda restoration.com

sixthwisconsin · « **Reply #9 on:** March 13, 2019, 06:34:58 PM »

I guess that is my conundrum.

Why is F0 production only two months and F1 19 months? Why did Honda, upon introducing the F model, change model years with virtually no changes after two months?

jlh3rd · « **Reply #10 on:** March 13, 2019, 06:51:26 PM »

yeah.....there's a guy i use for questions like this, he's got a 75, 750F in his shop. I'll see him tomorrow, he an indian and early honda expert........i wonder what the Honda Guidebook says.....

sixthwisconsin · « **Reply #11 on:** March 13, 2019, 07:09:32 PM »

Yeah, my bike was really a bastard when I got it. I THINK it was originally RED so that would jive with the frame #.

754 · « **Reply #12 on:** March 13, 2019, 07:51:35 PM »

Bthey changed colors, and rear master cylinders.. coukd be more..

Jerry Rxman Griffin aka MuthaF'er · « **Reply #13 on:** March 13, 2019, 09:13:51 PM »

Frank, the rear master changed from nylon? cup to full aluminum about half way through the F0 run at about 7500 or so

Don R · « **Reply #14 on:** March 14, 2019, 01:13:52 AM »

Honda was sued by a states attorney in new York for retitling left over bikes as the new model year. They lost in 75 and paid me $37 for my retitled K2 as a 1973 500 four. Even when asked the dealer looked my brother and me in the eye and told us it wasn't left over it was the latest model. My brother worked there at the time.
Honda immediately went into 76 production, I'd assume to prove a point. it's not just F's there are fewer 75K's also. There is nothing wrong with the 75's, it was just business.

jlh3rd · « **Reply #15 on:** March 14, 2019, 05:25:02 PM »

seems this would make the 75 F collectible...

BenelliSEI · « **Reply #16 on:** March 15, 2019, 05:11:45 AM »

Looking through these numbers, it looks like seems about 15,000+F0 frames and 15,000+ engines were manufactured in Jan-Feb of 1975. Next, Honda built about 22,000+ F1 frames and 38,000 F1 engines? Where did the extra engines go?

Heading out to check the numbers on my ‘75 cb750F?? today!

Jerry Rxman Griffin aka MuthaF'er · « **Reply #17 on:** March 15, 2019, 06:30:09 AM »

That sounds correct but there are F0's with VINs in March and early April. Perhaps the extra engines were used in the European F2 which was basically a F0/F1. Memory a little cloudy here.

david 750f · « **Reply #18 on:** March 15, 2019, 07:17:16 AM »

I don’t think the frame serial numbers posted reflect total worldwide production, possibly only US market bikes.
My F1 (Canadian bike) has Feb 76 build date with a frame VIN of 2022146. That is at the end of the serial numbers posted above.

BenelliSEI · « **Reply #19 on:** March 15, 2019, 11:13:44 AM »

........ out of curiosity I checked my cb750F today (Canadian Bike). Build date of Feb/‘75. Frame number: 1005704, so appears to be the 5,703rd built. Engine number: 2505758, 5,754th engine....... seems to line up nicely with the first chart. Nice to know. Thanks.

jlh3rd · « **Reply #20 on:** March 16, 2019, 05:57:26 AM »

Quote from: Jerry Rxman Griffin aka MuthaF'er on March 15, 2019, 06:30:09 AM

That sounds correct but there are F0's with VINs in March and early April. Perhaps the extra engines were used in the European F2 which was basically a F0/F1. Memory a little cloudy here.

i don't have a dog in this fight, but like learning stuff.....so here are pics of a 75 F mfd plate and then a "76" F. Notice the lower right corner of the plate under the word " motorcycle ". The 1/75 mfd date does not say anything under motorcycle. The 4/75 says "1976" model.
So, you're saying there are Fo's , mfd. in march/ april that would not have "1976 model" stamped on it?....

Jerry Rxman Griffin aka MuthaF'er · « **Reply #21 on:** March 16, 2019, 07:57:20 AM »

No, I saw a picture of a 1975 CB750F VIN plate that had a mfr date of 4/75. My take here is that your 1976 is a late 4/75 bike and the 1975 model I saw was an early first week 4/75.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #22 on:** March 16, 2019, 08:03:46 AM »

In Europe there were only F1 and F2 and as far as I know no "black engine" F's. They were basically the US F1 model with a double stay front fender with early K turn signals and the F0/F1 engine which could account for the "extra" engine serial numbers

ofreen · « **Reply #23 on:** March 16, 2019, 10:22:12 AM »

Quote from: sixthwisconsin on March 13, 2019, 06:34:58 PM

Why is F0 production only two months and F1 19 months? Why did Honda, upon introducing the F model, change model years with virtually no changes after two months?

Legend has it Soichiro himself hand-built the '75 F0s. A herculean task even for Soichiro, however special effort was warranted for a special bike. But after a couple of months he figured that was enough, handed off production to the assembly line and the '76/F1 was born.

jlh3rd · « **Reply #24 on:** March 16, 2019, 10:32:38 AM »

Quote from: ofreen on March 16, 2019, 10:22:12 AM

Quote from: sixthwisconsin on March 13, 2019, 06:34:58 PM
Why is F0 production only two months and F1 19 months? Why did Honda, upon introducing the F model, change model years with virtually no changes after two months?

Legend has it Soichiro himself hand-built the '75 F0s. A herculean task even for Soichiro, however special effort was warranted for a special bike. But after a couple of months he figured that was enough, handed off production to the assembly line and the '76/F1 was born.

I heard that, they would bring them over to the old folks home he was living at. What a guy.

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Author Topic: 750f0 - two month production? (Read 4116 times)